Aad, G.Abbott, B.Abed Abud, A.Abeling, K.Abhayasinghe, D.K.Abidi, S.H.AbouZeid, O.S.Abraham, N.L.Abramowicz, H.Abreu, H.Albert, JustinAnelli, Christopher R.Chiu, Y. H.Ghasemi Bostanabad, M.Hamano, KenjiHill, Ewan ChinKay, E. F.Keeler, RichardKowalewski, RobertLefebvre, Michelet al.2021-03-292021-03-2920202020Aad, G., Abbott, B., Abbott, D. C., Abed Abud, A., Abeling, K., Abhayasinghe, D. K., … Zwalinkski, L. (2020). Measurement of the Z(→ ℓ+ℓ−)γ production cross-section in pp collisions at √s = 13 TeV with the ATLAS detector. Journal of High Energy Physics, 2020(54). https://doi.org/10.1007/JHEP03(2020)054https://doi.org/10.1007/JHEP03(2020)054http://hdl.handle.net/1828/12815The production of a prompt photon in association with a Z boson is studied in proton-proton collisions at a centre-of-mass energy s√ = 13 TeV. The analysis uses a data sample with an integrated luminosity of 139 fb−1 collected by the ATLAS detector at the LHC from 2015 to 2018. The production cross-section for the process pp → ℓ+ℓ−γ + X (ℓ = e, μ) is measured within a fiducial phase-space region defined by kinematic requirements on the photon and the leptons, and by isolation requirements on the photon. An experimental precision of 2.9% is achieved for the fiducial cross-section. Differential cross-sections are measured as a function of each of six kinematic variables characterising the ℓ+ℓ−γ system. The data are compared with theoretical predictions based on next-to-leading-order and next-to-next-to-leading-order perturbative QCD calculations. The impact of next-to-leading-order electroweak corrections is also considered.enHadron-Hadron scattering (experiments)ArticleDepartment of Physics and Astronomy